Exploring Diabetes and Depression in Youth (EDDY) is a response to RFA-DK-02-009: Depression and Mental Disorders in Diabetes, Renal Disease, and Obesity / Eating Disorders. EDDY will focus on depression and diabetes in 10 to 19 year old youth at two ethnically diverse sites: South Carolina and Colorado. EDDY is an ancillary study to SEARCH for Diabetes in Youth, a CDC- and NIDDK-funded, multisite investigation for population-based case ascertainment and classification of both prevalent and incident cases of diabetes in youth. This case-cohort will allow investigation of the complex association between diabetes and depression in three major ethnic groups, African American, Hispanic, and Non-Hispanic Whites. Diabetes mellitus (DM) is the third most prevalent severe chronic disease of childhood, and a major cause of morbidity, mortality, and compromised quality of life. Childhood DM is now acknowledged to be a complex and heterogeneous disorder, with increasing rates of type 2 DM. A few smaller studies have found that children with DM are at higher risk for depression and that depressed children with DM may be at increased risk of poor management and complications. Existing studies have been small, and restricted to type 1 diabetes. The overall aim of this application is to explore the complex associations of depression and diabetes, which may differ for type 1 and type 2, in the SEARCH case cohort in SC and CO. We will examine the mutual impact of depression on diabetes management, glucose control, quality of life, and complications, as well as the impact of DM disease burden on the risk for depression. Specifically, we will estimate the prevalence and incidence of depression and related affective and anxiety disorders among youth with DM, and explore the correlates and predictors for depression among children and teens with DM, including parenting, self-efficacy, body image, and self-esteem. We will also investigate the impact of depression on diabetes management, clinical course, and complications in both type 1 and type 2 DM, and examine the extent of effective treatment for depression, and the impact of treatment on DM outcomes. Finally, we will explore the pathways involved in the association between DM and co-morbid depression and recurrent depression, with particular attention to disease burden, self-concept, obesity, and parenting.